


Cleaning Day

by ShitL0rd



Category: Undertale (Video Game)
Genre: Cuddles, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), Ectobiology, M/M, Porn, Sibling Incest, Soul Bond, Soul Sex
Language: English
Status: Completed
Published: 2017-02-06
Updated: 2017-02-06
Packaged: 2018-09-22 08:23:50
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 4,464
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9596135
Author URL: https://archiveofourown.org/users/ShitL0rd/pseuds/ShitL0rd
Summary: Sans accidentally left his laptop open with some explict pictures and videos.Papyrus is cleaning the house, and has suddenly ran into the lewd abominations!It's so dirty!... Yet...Strangly arousing....





	

**Author's Note:**

  * For [Octogator](https://archiveofourown.org/users/Octogator/gifts).



It was Cleaning Day! Papyrus truly enjoyed cleaning day. Out of all the days of the week, It was one of his favorites! Of course... there was always a downside. Cleaning Day's downside was...Sans. Well, his brother's bedroom to be exact! It took nearly as long to clean his brother's room as it took to clean the rest of the house. Still, It would not be Cleaning Day if The Great Papyrus did not tackle his messy brother's room! That in mind he pushed open his brother's door!

Oh, stars... It was worse than last week.

Socks were everywhere, the trash tornado was flinging papers about and his brother's sheets were balled up in a corner of his bed. Sans had even left his laptop open in the center of the mattress. That didn't seem safe at all. With a shake of his head Papyrus deposited the empty laundry basket next to the closest collection of socks. First things first he should move the computer to the desk, he would hate to damage it in his cleaning frenzy after all!

With that in mind, he picked up the laptop. As the computer woke up it let out a loud moan, almost startling Papyrus into dropping it. What in Asgore's name had Sans' been watching?! Where were that woman's clothes? Why was that man... Oh, stars. Papyrus really should turn off this lewd display. He... he should turn it off and pretend this never happened. Yes, that would be a great idea! Still... The lanky skeleton couldn't pull his sockets away from what was happening on the screen. A bright orange blush dusting his cheekbones... Stars, when did his Battle Body get so warm... and tight...

***

Sans had never moved so fast in his entire life. Sweat beaded at his skull as speed walking went to running.

He became conscious of the monsters staring at him as he sped through Snowdin. Must've been weird seeing the village's laziest citizen running like their ass was on fire.

Sans regrets everything now. He wasted all of his magic at Grillby's on lifting hotdogs in the air as high as he could. Doggo had mentioned the word 'computer' and good god, Sans had really fucked up.

Of all the days he left his laptop on display...

The small skeleton swung the front door open, panting hard. He was not used to such a strenuous activity.

***

Papyrus didn't hear the front door open. His attention was... elsewhere. He knew what was going on. He was an adult after all! He always thought someone so very great as himself above the act of watching something as lewd as pornography. A wet slapping noise paired with several moans and grunts sounded so loud in the empty room, It caused the skeleton to flush even darker. Sans shouldn't be home for a while, normally his lazy brother would avoid the house entirely on Cleaning Day... Papyrus would have time-

Oh, Stars. What was he thinking! He couldn't! He shouldn't! Certainly not in his brother's room. It would be improper! What would Sans think? If he found Papyrus in here watching this and... It mortified him. Stars he... Maybe he could just take the edge off? The rush of magic to his pelvis was certainly not a problem that would go away soon. As he knelt on his brother's bed, setting the laptop in front of him, Papyrus let his fingers wrap around his spine stroking the vertebra just above his pelvis. His breath came out in a short needy puff as his sockets focused on the video. Was this the type of thing Sans was into?

***

Sans rushed up the stairs, breathing heavily. We kept his balance by holung onto the stair railing for dear life.

He finally made it to the top, but could hear a very familiar video playing in his room. He could just sneak in there, grab the laptop, and make another feeble attempt of hiding.

Just as Sans turned the corner, he got the sight of a lifetime. He could feel his face burn and his soul flutter in response to the scenery.

He couldn't just stare! It's really creepy... But Sans also felt guilt. Maybe Papyrus was curious and- no! This is his job to keep his bro safe and keep him out of harm's way!

But... Papyrus wasn't really in danger.

Sans released a strained "uh" to catch the attention of his sibling

Papyrus let out a shriek and snapped the laptop shut ripping his fingers away from where they had been inching closer to his pelvis.

"S-SANS!? I ER... I DIDN'T HEAR YOU COME HOME!" His face felt like it was on fire. He couldn't bare to look Sans in the eye. His soul was pounding so hard against his ribcage that it ached. To make matters WORSE his magic still hasn't calmed down for what he was about to do. What he was about to do on his brother's bed.

Papyrus shifted his gloved hands to try and hide the tale glow shining through his shorts. There was no point being subtle about it when it was clear enough what Papyrus was about to do.

Sans blushed at how utterly surprised and flustered Papyrus looked. Though, he could say the same about himself.

Without making eye contact, he shuffled into his room and shakily lifted his laptop. Sans could feel his soul shudder in need.

"uh..." he stared wide-eyed at the carpet. "s' okay. just..." /shit what do I say???/

Papyrus scooted away, far too ashamed to want to be near the offending laptop. He... Papyrus should say something... Do something.

But all he could really do was shake slightly, his soul feeling tight as he fought the urge to cry out of embarrassment.

"B-BROTHER... I... I SHOULD NOT HAVE- "He couldn't take this it was too much, even for someone as great as he was. Papyrus' eyes darted towards the doorway. "I'M SORRY BROTHER!" His words rushed out as he darted for the hallway, intent on fleeing to his room.

Sans' sockets widened in shock. He dashed towards his brother is shouted. "n-no bro! i'm not mad!"

Papyrus stopped in his doorframe clutching it as he took a deep breath, trying to fight down his embarrassment. "W-WHY NOT! WHAT... WHAT I WAS ABOUT TO DO WAS SO LEWD! I..." Papyrus took a deep breath, hiding his face in his hands as his voice softened. "I'm... disgusting."

Sans gasped and quickly hugged his brother. He shook his skull violently. "no you're not! it's normal t-to do that kinda stuff. its... it's my fault.."

Papyrus hesitated a moment before wrapping his arms around his brother. He's never been one to turn down a hug, and as embarrassed as he was it felt good to hold and be held by his brothers. It helped calm him down even if he was still a bit mortified. Papyrus tucked his face against his brother's shoulder before he began to speak. "Maybe... But... Doing it in your room isn't normal. This isn't your fault Brother."

Sans adamantly disagreed. Though, he couldn't bear to look his brother in the eyes. He couldn't allow Papyrus to feel responsible for /his/ mistake.

"yeah it is. i left that out in the open, and i knew it was cleaning day..."

Papyrus pulled back, just enough to try and look at his brother. He would NOT have Sans blaming himself for the lewd actions Papyrus choose to take. "SANS! I COULD HAVE CLOSED IT, I CHOOSE TO CONTINUE WATCHING, I WANTED TO SEE WHAT YOU LIKED-" Oh. Oh, stars he didn't mean to say that last part. Now he was quickly turning dark orange again and started to pull fully away from Sans. "I mean... Nyeh heh heh" he laughed more out of nerves than anything else.

Sans gasped in shock. He stepped back a bit, trying his best to keep his smile from wavering. He shoved his mittened hands into his pockets for a sense of comfort.

"u-uhuh..." Sans flushed and stared at his slippered feet. "s' okay. r-really. i uhm... i don't really mind."

Papyrus fidgeted as he glanced from the floor to his brother's face and back. "Y-you don't? Then Can I ask..." Papyrus took a breath to gather himself before the rest of his sentence came rushing out all togeather. "WHAT-YOU-LIKE-ABOUT-THOSE-KINDS-OF-VIDEOS?!"

Sans flinched at Papyrus's abruptness. He shifted awkwardly, then sighed deeply. "u-it looks... good."

He then nervously looked to the side, his head still low. "and... it makes m-me feel good."

"have you ever felt that way?"

"I GRASP THE CONCEPT OF... IT. BUT I HAVE NOT BEEN ABLE TO PUT IT FULLY INTO PRACTICE." Papyrus flushed darkly as he admitted it. He knew where it felt good to touch, that it would cause his magic to pool in the cradle of his pelvis but never quite taking form.

He didn't really know what to do from there, and it seemed like such a pointless and messy exercise that he simply spent his time on other things. "Perhaps I am not doing it correctly." Papyrus mused.

Sans shuddered at the thought or Papyrus's inexperienced hands roaming his body. "w-wouldyoulikemetohelpyou?"

He held his breath.

Papyrus froze. He... did he really hear his brother correctly? Oh, Stars... He did. Papyrus flushed in a way that had nothing to do with embarrassment.

"Y-yes. YES!" Papyrus corrected himself after the first stuttering of the word.

Sans felt his soul leap at light speed. He continued to dip his head as he shuffled past Papyrus and into the bedroom.

He stood awkwardly next to the awesome race car bed and shuddered in anticipation.

Papyrus followed behind Sans, perching on the edge of his bed. He glanced up at Sans for a moment before becoming very interested in his knees. He felt like he was buzzing with excitement and nerves.

Sans held his breath and turned gingerly. He placed two shakey hands on each of Papyrus' legs, and ran his fingers along the tight black fabric. He then began to feel around those perfect, wide hips.

"y-you okay?"

Papyrus' voice caught in his non-existent throat as he let out a little gasp. It felt so different having someone else's fingerbones touching him.

Another little line as fingers passed over a sensitive section of his hipbone. "Y-Yes Brother... Are-are you okay?" He questioned, wanting to check in with Sans.

Sans chuckled softly and kissed Papyrus on his teeth.

"You sure you wanna do this?"

Papyrus thought his soul was going to burst when Sans kissed him. He leaned into it, his hands coming up to grip the front of his brother's hoodie. Oh, stars... if kissing felt like this.

"Yes, Brother! I... I want to learn!"

Sans felt himself melt into the warm kiss. He chuckled and used his blue magic to place Papyrus across the bed. He then joined his brother and resumed caressing him.

"w-what do you wanna do first?"

Papyrus shifted, hesitantly resting one of his hands against his brothers ribs and copying the caressing motion.

"Maybe... With what was happening in that video? It... Looked like a lot of fun." Papyrus flushed darkly.

Sans pushed against Papyrus's returning touch. He hunched slightly and slipped his hand down and brushed his fingers over Papyrus's pelvis.

"m'kay... let m-me know if you want to stop."

"P-please don't stop." He couldn't stop himself from grinding his pelvis against his brothers hand, his fingers stroke in a bit harder against his brothers ribs.

"Nyeh... Sans." Papyrus panted, he could feel his magic starring to respond to his brothers touch, making him more sensitive.

Sans felt his tongue fill his mouth in hunger. He leaned into the crook of Papyrus's neck nibbled on the soft cartilage. Sans pulled down his brother's pants and tugged lightly on the pelvis.

"y-you know how to conjure stuff?"

The attention to his neck drew something close to a moan from Papyrus. It sent a spike of arousal and pleasure through him. "I can make a tongue..." Papyrus shifted back enough to show his brother his own freshly conjured tongue, it was a long and slim muscle. "As for the rest... I've... er... never got the hang of it."

Papyrus gave a nervous chuckle at his own ignorance as he took a moment to peel off his gloves before returning his own hands to his brother.

Sans whined at the sight of Papyrus's long, ivory fingers. He pulled one of them to his mouth and suckled on one of them. Sans could feel his shorts tighten from his arousal.

"u-uh, okay," he calmly stated. He then turned a light blue. "is okay to show mine?"

Oh... Stars, he couldn't help but press his finger against his brother's tongue as he sucked on it. It was so lewd. At the question, Papyrus' sockets practically sparkled. "Yes! Maybe... Maybe if I can see yours I can figure out how to make one!" Papyrus grinned, turning his attention to his brother's shorts.

Sans groaned against Papyrus's finger and silently pulled down the front of his shorts, freeing his small throbbing erection. Pre was already dripping from the slit.

Sans shuddered and pulled away from Papyrus's hand. "s-sorry it's not much..."

"It's beautiful." Papyrus could not stop himself from saying. His fingers quick to follow his brother, but stopping short a few inches away from actually touching Sans. Stars, he didn't know why but it was so hard to resist the urge to run his thumb over that bead of pre Cum and rub it into the head of his brothers cock.

Oh, stars. When did he become so lewd?

He pulled his sockets away from his brothers pelvis to try and meet his sockets. "Brother... Can I?" he questioned, fingers inching closer.

Sans inched his hips closer and gripped on Papyrus's shoulders. He released a heavy breath.

"f-fuck yes"

That was all Papyrus needed before his hand moved forward, fingers wrapping around his brothers cock, trying to mimic the hold and stroking motion he saw in the video.

"Is... this right?" Papyrus asked as he stroked. He could feel his magic starting to pool in his groin, attempting to take shape.

Sans squeezed his legs around Papyrus and bucked his hips. The other's touch was so cautious, inexperienced, and eager.

Sans ran his tounge along his brother's cheek and wheezed. "you're doing great, bro."

Papyrus groaned at the feeling of Sans bucking into him, rutting into his hand. It made him feel so hot, stars above, he wanted to do a good job. He gripped a bit firmer, pumped a bit faster.

But he nearly stopped when he felt the touch of something soft and wet against his cheekbones. Ah, Sans tongue... his own was still conjured. He remembered in the video there had been some very... involved kissing... maybe? Hesitantly Papyrus turned his head, opening his mouth to let his own tongue brush against his brothers.

Sans' eyes fluttered closed as he ravaged Papyrus' mouth. The feeling of that long tongue againt his broad one felt amazing. His soul pulsed brightly beneath his shirt, and noticed that his jacket was becoming too hot for him comfort.

Sans sat up and shrugged off the blue hoodie, then threw it in some vague direction. He flushed as he realized how bright his soul was.

Papyrus moaned into his brother's mouth. This morning he didn't even think skeletons could really kiss like this... He's never been so glad to be wrong. Stars did he love the feeling of his brother tongue against his, pressing into him.

When Sans pulled back to undress It left Papyrus panting and needy. He wanted Sans to touch him, he wanted to touch Sans. "Aah... Brother." he whined, his eyes landing on the pretty glow behind his brother's ribs.

Sans chuckled nervously and lowered himself between Papyrus' long legs. He held onto his cock and grinded against his brother's pubic arch.

Sans huffed and spoke in low breaths. "you gotta... concentrate... and think real hard, t-then it'll show up"

That felt amazing Papyrus hooked his fingers around Sans lower ribs, clinging to his brother as he shut his sockets and focused. He was 'The Great Papyrus!' he could manage something as simple as this. It took him a few tries before his magic finally took shape. In the form of wet, and quivering folds.

Sans blushed and glanced down at the perfect mound Papyrus provided him. It glistened and had a very distinct, sweet smell.

He pulled himself away, not wanting to pound into his bro immediately. "oh stars, papyrus..."

"Nyeh... Is it... alright brother?" He cracked opened a socket to look at his brothers blushing face. Papyrus himself was blushing so hard he was practically glowing. he couldn't help the small twitch of his hips when Sans moved away, he missed that contact. He wanted, no. He NEEDED to be touched.

Sans lowered his head. "s' perfect, Papyrus," he murmered. He slipped out his tongue and ran it along the outer folds, tasting the sweet fluids.

Sans then used his right hand and shakily spreat the labia apart. He huffed and nuzzled against Papyrus' clit.

"Brother what are you- Ah!" Papyrus gasped, throwing his head back. He had not been expecting something like this. He bucked slightly against his brothers face, letting out a needy whine.

"Oh, Stars... Please, Sans." he new he was rambling, but it felt so good, and the sight of Sans between his femurs did more for Papyrus then pornography ever did.

Sans groaned as he felt his brother buck into his face. His erection throbbed in excitement and he dipped his tongue into the tight passage.

Sans played with his brother's clit in time with the strokes of his tongue.

Papyrus clenched his conjured passage around the invading tongue. Stars above did that feel good. It was almost too much combined with Sans playing with that little button of ecto-flesh near the top of it. "Nyeh- ah- brother." His voice was begging for more.

Sans whined and pushed his tongue deeper, then flattened it, causing the flesh to stretch. He hummed in bliss and closed his eyes.

Papyrus moaned, shuddering at the feeling of his brother's tongue filling him. His legs hooked around Sans back, pulling him closer. He felt something building a pressure, and a deep primal need and want for more.

"S-Sans, some- nyghh something's happ-ening."

Sans began to hump his own hand at the feeling of Papyrus tightening around him. He used his other hand and began to pump a finger into Papyrus' opening.

"mmh, let it out, bro," Sans whispered.

It was scary, it felt big. Like he was going to burst. But he trusted his brother, he trusted Sans. Papyrus let out several short whiny moans as he neared his peak. When Sans' fingers joined his mouth Papyrus' hands found the back of his brother's head, pushing him against his mound as he came. "S-Sans!"

Sans's eye lights rolled to the back of his skull in euphoria. He squeezed the head of his dick hard, keeping himself from coming.

Sans pulled away, flushed a deep blue. The light orange fluid was streaked across his teeth. "stars, you t-taste good."

Papyrus was flushed and sensitive. It felt like his summoned parts were still twitching from what he experienced. "Wowie Sans..." He breathed, flushing darkly at his words. "I do?" He leaned forward, running his tongue across his brother's teeth and tasting himself.

"Nyeh... Brother... Can we? I still want more." He whined, letting his hand rub down his brother's sternum and spine, stopping at the base of his cock.

Sans groaned and leaned forward into Papyrus' touch. "mnh, i'm gettin tired..."

He then leaned back and proped himself on his elbows. Sans spread his legs wide and blushed a deep blue. "how bout you ride me?~"

Papyrus chuckled, crawling over Sans to chase the contact. He pressed his teeth to his brothers as he positioned himself so he was hovering over his brother's hips some of his leftover slick dripping down onto his brother. Stars above... It was so lewd.

"Like... This brother?" Papyrus questioned, his nerves showing in the quiver of his voice as he lined up his brother's cock to his entrance.

Sans stared at his brother with lidded eyes. He placed his hands on both hips and grinned slightly. "you're doin great."

He shuddered as his cock twitched in anticipation. Sans grunted and lifted himself, brushing against Papyrus' wet folds.

"Ah, Sans!" Papyrus moaned at the touch, lowering his hips down onto his brother. It was so much thicker feeling than he expected. It left him shivering at the feeling of being stretched.

Papyrus moved slowly, until his hip bones rested against Sans', having hilted his brother. He was panting as he caught his breath, getting used to the strange feeling of being filled.

Sans gasped at the intense feeling. His toes curled and he couldn't keep himself from squirming pitifully.

"m-mnh," Sans glanced down and noticed how much Papyrus was taking. His thickness make up for the length. "t-take yer time, P-Paps..."

Star above was his brother thick. If Papyrus had eyes they would have rolled back in his head as he started bouncing slowly, easing more and more of Sans into him. The stretching was a strange thing for him. It hurt, but it felt amazing. He loved it, he understood the appeal of all of this, how could someone not want to feel this good?

"S-sans, Nyeeh, You feel so good inside me brother." Papyrus flushed darkly at the lewdness of what he said.

Sans grinned and bucked his hips gently into Papyrus' movements. He ran his hands back and forth along his brother's femurs, trying to ease any discomfort.

Drool began to slip down his chin. "fff-fuuck, paps." Sans could not think of anything else. All he could was chant Papyrus' name and whine.

It really didn't take long at all for the pain to be forgotten in place of how good it felt. Papyrus started to move faster, in border motions up and down his brother's length. Letting out little whines and moans of his own.

"Nngh, Language brother." Papyrus scolded, slamming his hips down a bit harder than before and letting out a loud moan.

Sans wheezed at the slam against his cock. He arched his back and began to pant heavily, his soul pounding against his ribcage.

Sans' soul began to push through, causing his tshirt to get wet. He squirmed and rutted his hips a few times.

Papyrus braced himself with his hands on either side of Sans head. His chest close enough to his brother's that his own soul starred to glow brighter and push against the interior oh his battle body.

After a moment Papyrus leaned forward enough to kiss his brother, his hips falling back into a steady motion.

Sans wrapped his arms around Papyrus's broad shoulders and shivered. His soul finally pushed through. It quivered in need, coaxing the other to come out.

Sans whimpered and grunted incoherent murmurs into Papyrus's mouth as he kissed him.

Papyrus' own soul was happy to push out and join his brothers. Papyrus' didnt notice at first. He was so focused on chasing that building peak, on pulling more beautiful sounds from his brother.

When Papyrus broke the Kiss his eyes fell to the glowing hearts between them. "Nyeh- Ah... Brother.. Your- my-" He was cut off by a moan as he came down, Sans brushing against a particularly good spot inside of him.

Sans sputtered a few curses as he felt Papyrus' soul beginning to merge with his own. He reached his arms and pulled his younger brother back down. "i w-wanna hold you tight..."

Sans pushed back into Papyrus' quivering walls, feel himself reaching his peak as well.

Papyrus moaned, wrapping his arms around his brother and pressing their souls togeather. He came, harder than he did the first time as his walls spasmed against his brother. "Brother. Ah! Sans!" He called out, clinging to his brother and burying his face against the side of his neck.

Sans gasped as the walls fluttered around his cock. He squeezed Papyrus closer to him and frantically bucked his hips into his brother. "ah, ahh-h oh fuck!!!"

Sans gave in to a violent thrust, and came heavily into Papyrus' pussy. Cum squirted out where it has squeezed through.

Oh, Stars was that different. Feeling his brother fill him to the point that it oozed out of him. It was so lewd and messy. But he loved it, this pleasure, this closeness to Sans. It was worth a little mess.

Papyrus ground their hips togeather slowly as he came down from his orgasm, letting out a content sigh when he finally stilled.

Sans relaxed into the cushion of his brother's bed, not wanting pull out of him any time soon. This feeling of connection was unfathomable.

Sans could feel his soul twist in... Sadness? Why would he be sad after literally the best thing that ever happened? He hoped to Asgore that Papyrus wouldn't sense the sudden shift in his aura. "that... that was great, papyrus." Sans could feel himself choke up on his words.

Papyrus was more than happy to enjoy this closeness to his brother, wrapping his arms around Sans and letting their souls gently rub togeather as he came down from the blissful encounter. He felt the pulse of sad, It confused him at first because why would Papyrus feel sad in this situation? It took him a moment to realize that it was coming from Sans.

"Brother? Sans?" He pulled back, cupping Sans' cheek as he looked into his brother's sockets, searching them. He couldn't hide the worry from his face. "Brother? what is wrong." He hummed softly.

Sans closed his eyes and leaned into Papyrus' warm hand. He felt a pang, realizing that he had now worried his beautiful bro. "huh, just... kinda emotional right now," he admitted bashfully.

Papyrus leaned down, nuzzling his teeth against his brother's skull. "Do you want to talk about it, Sans? It might help." Papyrus hummed, letting his soul pulse with love and caring directed towards his brother.

Sans shook his head gently. "seriously. i'm just a lil sensitive after our little..." He flushed a deep blue. "-love session."

Papyrus hummed and let his fingers trace lightly over Sans ribs in an affectionate manor. "I love you brother. Thank you for doing this with me."

Sans kissed Papyrus on the cheek and chuckled. "oh, stars. i should be thanking YOU." He then held in a whine as his cock began to slowly dissipate, wanting to stay connected like this forever....


End file.
